Isoalloxazines



U fi S tes Paint;

rsoAriroxArznvns Harold G. Petering, Kalamazoo, and Harry H. Fali,Kalamazoo Township, Kalamazoo County, Mich, assignors to The UpjohnCompany, Kalamazoo, Mich, a corporation of Michigan No Drawing.Application May 24, 1955 Serial No. 510,87ii

17 Claims. (Cl. 256-2515) atoms. The esters are represented by thefollowing general formula:

R2 l 2)n I 8 wherein n is an integer from two to six inclusive, R is amember selected from the group consisting of (a) an acyloxy radical, theacyl group of which is derived from an organic acid with not more thaneighteen carbon atoms; (b) a sulfate radical; and (c) a phosphateradical; R and R are members selected from the group consisting ofloWer-alkyl, lower-alkoxy, amino, hydrogen, halo, and a polymethylenegroup linked to the aromatic ring to form a carbocyclic ring having sixcarbon atoms; R and R are members selected from the group consisting ofh drogen, lower-alkyl, lower-alkoxy, and amino, and wherein R R R and Rwhen taken together, include not more than one amino group.

The terms lower-alkyl and lower-alkoxy as used herein include alkyl andalkoxy groups containing from one to five carbon atoms inclusive.

Sulfate and phosphate are generic terms referring respectively to theradicals obtained by removal of one or two atoms of hydrogen fromsulfuric acid and to the radicals obtained by removal of one, two orthree atoms of hydrogen from phosphoric aci It is an object of thepresent invention to provide novel compounds. Another object of thisinvention is to provide a process for the preparation of thesecompounds. Other objects of the invention will be apparent to thoseskilled in the art to which this invention pertains.

The novel compounds of the invention possess antimetabolite activity;for example, they are competitively active riboflavin antagonists. Thesecompounds also exhibit anti-psittacosis activity. I The[w-hydroxyalkyl]-isoalloxazine esters of the invention are characterizedby unexpectedly superior antiribofiavin activity when compared with thecorresponding [w-hydroxyalkyl] isoalloxazines. For example, antiriboflavin activity up to five times the magnitude possessed by the[w-hydroxyalkyl]-isoalloxazine has been displayed by the correspondingester compounds.

2,825,729 Patented Mar. 4-, 1958 I l B3 T o=o l NH RP \li/y in ('5wherein n is an integer from two to six inclusive, and R R R, and R areas defined above, with an esterifying agent to obtain the correspondingisoalloxazinealkyl ester.

Conversion of an [w-hydroxyalkyl]-isoalloxazine to the corresponding[w-hydroxyalkyl]-isoalloxazine ester is achieved by a variety ofprocedures. In one method, the lw-hydroxyalkyll-isoalloxazine isrefluxed with an excess of an organic acid in the presence of a catalystsuch as hydrogen chloride, sulfuric acid, toluene sulfonic acid, or thelike. A preferred procedure for the preparation of an[w-hydroxyalkyl]-isoalloxazine ester embodies the alcoholysis of eitheran acid chloride or an acid anhydride'of an inorganic acid such assulfuric acid or phosphoric acid or an acid chloride or acid anhydrideof an organic acid with not more than eighteen carbon atoms. The acidchlorides and acid anhydrides of the organic acid usually react morereadily and rapidly with the [w-hydroXyalkyH- isoalloxazine in thepresence of a basic material such as sodium carbonate or an organictertiary amine such as pyridine. Acid chlorides and acid anhydrideswhich are used to esterify [w-hydroxyalkyll-isoalloxazine include aceticanhydride, acetyl chloride, propionyl chloride, propionic anhydride,benzoyl chloride, lauroyl chloride, succinic anhydride, succinylchloride, or the like; a phosphoric acid chloride such aschlorophosphoric acid or phosphoryl chloride; or a sulfuric acidchloride such as chlorosulfonic acid or sulfuryl chloride.

The term organic acid as used herein includes both monoandpoly-carboxylic acids such as acetic acid, phenylacetic acid, propionicacid, cyclopentanepropionic acid, benzoic acid, lauric acid, myristicacid, stearic acid, oleic acid, p-aminobenzoic acid, salicylic acid,p-aminosalicylic acid, pimelic acid, succinic acid, glutamic acid,phthalic acid, pantoic acid, aspartic acid, adipic acid, glutaric acid,maleic acid, itaconic acid, citraconic acid, aconitic acid, subericacid, tetradecanedioic acid, azelaic acid, dodecanedioic acid, sebacicacid, brassylic acid, thapsic acid, octadecanedioic acid, tetrapropylsuccinic acid, n-tetradecyl succinic acid, a-aminoacetic acid,aaminopropionic acid, ,B-aminopropionic acid; an alkane sulfonic acidsuch as methane sulfonic acid, ethane sulfonic acid, butane sulfonicacid, and the like; an aryl sulfonic acid such as benzene sulfonic acid,toluene sulfonic acid, naphthalene sulfonic acid, and the like; analkane phosphonic acid such as methane phosphonic acid, ethanephosphonic acid, butane phosphonic acid, and the like; an arylphosphonic acid such as benzene phosphonic acid, toluene phosphonicacid, naphthalene phosphonic acid, and the like. When the organic acidsare polybasic, it is to be understood that unesterificd acid groups canbe neutralized by a base to form salts. The water-soluble salts such asthe sodium, potassium, calcium, magnesium, and the like, i. e., alkalimetal and alkaline earth metal salts, are particularly useful because oftheir high water-solubility which makes it possible to obtainconcentrated preparations in infusion solutions or other suitablevehicles especially useful for parenteral, oral or topicaladministration. The preferred acids are the hydrocarbon carboxylic acidswith not more than eighteen carbon atoms such as acetic acid, propionicacid, benzoic acid, succinic acid, 'lauric acid, myristic acid, and thelike.

used as the starting material.

" V v V 2,825,729 M i T The starting [-w-hydroX'yalkyl]-isoalloxazinesare obtained by reacting a polyhydroxyalkylisoalloxazine of the formula:

where in R R R and R are as defined above, m is an 7 integer from one tofive inclusive; and n' is an integer from one to four inclusive, withnot more than 2.5 times n equivalents of an oxidizing agent such asperiodic acid, lead-tetraacetate, or the like, per mole of polyhydroxy--alk-ylisoalloxazine-, to produce the corresponding [toformylalkyl]-is6alloxazlne of the formula:

wherein R2, R R1; and R are as defined above and R is an w-formylalkylgroup containing from two to six carbon atoms inclusive, and thenreacting the [w-forrnylarylazo compounds with barbituric acid in an acidmedium (U. S. Patent 2,261,608).

Ortho-aminoarylazo compounds can also be condensed with alloxantin ordialuric acid to produce isoalloxam'nes in accordance with the proceduredisclosed in U. S. Patent 2,374,661.

The starting aminoazo compounds are conveniently prepared by couplingsubstituted phenylamines containing alkyl, alkoxy, halo groups,-andthelike, with a diazotized amine in the manner described by'Kar'rer, Helv.Chim. Acta, .18, 1130, 1935,19,.264-[1936 In another method used in thesynthesis of isoalloxazines, the need for the above-indicated aminoazocompounds is eliminated siiic'e N-s'ubstituted' aromatic amines such asribityl or arabityl xylidine, and the like, or mineral salts thereofsuch asthe hydrochlorides, or the like, can be condensed directly withvioluric acid to yield isoalloxazines in a single step. 7

In another method, polyhydroxylated alkyl nitrile's or their acylderivatives can be'reductively condensed'with an aromatic amine" to formthe corresponding N polyhydro'xyla'ted alkylam'ine or the acylatedN-polyhydrox'ylated alkylamine, Which compound can then be coupled witha diazonium salt, theresulting compound reduced to form thecorresponding diamine'an'd' the diamine thus obtained condensed withalloxan to form an isoalloxazine (U. S.

Patent 2,261,608).

the corresponding formylalkylisoalloxazine with not more than times nequivalents "of oxidizing agent per mole ofpolyhydroxyalkylisoalloxazine, as indicated supra, the

term equivalent refers to the molecular weightof the 'oxi-' dizing.agent divided by the valence change of the oxidizing agentinvolved inthe reaction. a a e The polyhydroxyalkylisoalloxazines are prepared byknown methods. For example, in one method, apolyhydroxyalkylisoalloxazine is obtained by subjecting an N-monosubstituted aromatic ortho-diarnine to condensation with an alloxancompound (Ku hn, Ben, 67, 1939,,1 934; Karrer, Helv. Chim. Acta, 18, 69,1935). The condensation of the N-monosubstituted aromatic ortho-dia'mineWith alloxanf or N-mon'osubstituted products thereo-f to produce theisoalloxazine is. preferably performed in an acid solution, forinstance, in the presence of a mineral acid sucli as hydrochloric,hydrobromic, sulfuric, nitric or phosphoric acid; but the condensationcan also as carried outin a strong acetic acid solution, preferably bymixing the N-polyhydroxyalkyl; aromatic ortho-diamine' with a suspensionof alloxan monohydrate and boric acid in glacial acetic acid,thedesiredisoalloxazine thus formed usually precipitating from the reactionmixture in substantially pure form.

Instead of using an N-monosubstituted aromatic orthodiamine in theabove-described condensation process, an

N-monosubstituted aromatic ortho-nitroarnine can be The reduction of theorthonitroamine to the corresponding diamine and the subsequentcondensation with alloxan can be carried out in a single step if the Nurone-substituted aromatic orthonitroamine is reacted with the alloxancompound in the presenceiofa reducing agent.- Reducing' agents which canbe usedinclude tin, stannous chloride, iron, trivalent titaniu'm, andthe like; A leuco'compound of the isolloxazine compound is formed whichis subsequently dehydrog'iiated by treatment witha dehydrogenating'agent. Suit a'ble dehydrogenating agentsflsuc'n as atmospheric oxygen,potassium permanganate, halogens, quinoid dyes'tuflfs, and the'like',can be used. j a

Isoa'lloxa'zines are also prepared by reacting orthoafnitioarylaz'ocompounds of ring-substituted ortho-amino- D-ribamine with alloxan toyield riboflavin.

The various 6,7 dialkyl 9 polyhydroxyalkyliso ah loxazines which areused in the preparatio'r'iof 6,7-'

dialkyl-9-[w-formylalkyl]-isoalloxazines canals'o be ob-' tainedaccording to the method of Karrer et' al.,' Helv. Chim. Acta, 17, 1165,1516, (1 934).

A typical polyhydroxyalkylinoalloxazine, riboflavin, otherwise referredto as 6,7-diniethyl-9=(1'-D-ribityl)-isoalloxazine, Was synthesized byKarrer, Helv. Chim. Acta,

(l) condensation of 4-5-dinitro-o-xylene'with D-ri-baminef followed bycatalytic reduction, in" an aqueous alcoliolic solution, of the" productthus" obtained (Kuhn and Weygand, Ben, 68, 1001, 1935); or (2)condensation of 3,4-dimethyl-6-nitroaniline with D-ribose and reductionof the product thus obtained (Kuhn et' a1, Beri, 68, 1765, 1935; 70,773, 1937); or (3), condensation of 3,4 dimethyl 6carbetho'xyaminoanilirie (Karrer et a1., Helv. Chim. Acta, 18, 69,1935;18, 426, 1935) or 3,4 dimethyl 6 acetylaminoa'niline (Kari-er etah, Ben, 68, 216, 1935) with D-ribose,- reduction and saponification ofthe resulting compound to obtain the flee amine, N (3,4 dimethyl 6aminophenyl) D- ribamine; 'or (4), condensation of 3,4-dimethylanilineWith D-ribose, catalytic reduction of the resulting riboside to N (3,4dimethylphenyl) D ribamine', coupling zines, including those containingsubstituentsin' mes, 6, V

7 and 8 positions, can likewise be prepared. Thus, the[w-formylalkyl]-isoalloxazines media the preparation of the[w-hydroxyalkyl]-isoalloxazines can be obtained by any of the proceduresdescribed supra or other conventional methods disclosed in the art.

P The following preparations and examples are illustrative of theprocess and products of this invention but are not to be construed aslimiting.

PREPARATION 1.6,7-DIMETHYL-9-LB-HYDROXYETHYL1- IsOALLoxAztNE 28.4 grams(0.10 mole) of 6,7-dimethyl-9-formylmethylisoalloxazine, obtained byreacting 6,7-dimethyl- 9-(l'-D-ribityl)-isoalloxazine (Karrer at 2.1.,Helv. Chin-1. Acta, 17, 1516, 1934) and periodic acid, is suspended in250 milliliters of 0.4 N sodium hydroxide. (To prevent decomposition,the reaction mixture is shielded from light.) A solution of 3.7 grams(0.10 mole) of sodium borohydride in 25 milliliters of water is addedthereto. An immediate reaction occurs as indicated by the formation of agreenish precipitate. After stirring for two hours, the mixture iscooled in an ice bath and the pH adjusted to pH 4.0 to pH 4.5 withglacial acetic acid. The solid material thus obtained is removed byfiltration and then washed successively with acidified water, acetoneand ether. After drying at a temperature of about sixty degreescentigrade, there is obtained 25.3 grams (88.4 percent yield) of ayellow solid, 6,7-dimethyl 9 [,8 hydroxyethyl] isoalloxazine, meltingbetween 299 and 301 degrees centigrade, uncorrected.

PREPARATION 2.6-ETHYL-7METHYL-9-[fi-HYDROXY ETHYL1-ISOALLOXAZINEFollowing the procedure described in Preparation 1 except for thesubstitution of 6,7-dimethyl-9-forrnylmethylisoalloxazine by 29.0 gramsof 6-ethyl-7-methyl- 9-formylmethylisoalloxazine (obtained by reacting6- ethyl 7 methyl 9 (1' D ribityl) isoalloxazine [Karrer and Quibell,Helv. Chim. Acta, 19, 1034, 1936] with periodic acid), 6 ethyl 7 methyl9 8- hydroxyethyH-isoalloxazine is obtained.

PREPARATION 3.5,6-D1METHYL-9-[5-HYDROXYETHYL1- ISOALLOXAZINE Followingthe procedure described in Preparation 1 xcept for the substitution of6,7-dimethyi-9-formylmethylisoalloxazine by 28.4 grams of5,6-dimethyl-9- formylmethylisoalloxazine (obtained by reacting5,6-dimethyl 9 (1 D ribityl) isoalloxazine [Tishler et al., J. Am. Chem.Soc., 69, 1488, 1947] with periodic acid), 5,6 dimethyl 9 [5hydroxyethyl] isoalloxazine is obtained.

PREPA ATION .4.-7ME'IHYL-9-[B-HYDROXYETHYL]- ISOALLOXAZINE Following theprocedure described in Preparation 1 except for the substitution Of6,7-dimethyl-9-formylmethylisoalloxazine by 27.0 grams of7-methyl-9-formy methylisoalloxazinc (obtained by reacting 7-methyl-9-(1-D-ribityl)-isoalloxazine [Karrer and Quibell, Helv. Chim. Acta, 19,1034, 1936] with periodic acid), 7- methyl 9 [,8 hydroxyethyl]isoalloxazine is Obtained.

PREPARATION 5.6,7-DICHLORO-9-[B-HYDROXYETHYL}- ISOALLOXAZINE Followingthe procedure described in Preparation 1 except for the substitution of6,7-dimethyl-9-formylmethylisoalloxazine by 32.5 grams of6,7-dichlorO-9- formylmethylisoalloxazine (obtained by reacting6,7-dichloro 9 (1' D ribityl) isoalloxazine [Weygand et al., Ber., 76,1044, 1943] with periodic acid), 6,7-dichloro 9 [B hydroxyethyl]isoalloxazine is obtained.

PREPARATION 6.67-DIMEm0xY-9-LB-HYDROXYETHYL1- ISOALLOXAZiNE Followingthe procedure described in Preparation 1 except for the substitution of6,7-dimethyl-9-formylmethylisoalloxazine by 31.6 grams Of6,7-dimethoxy-9- formylmethylisoalloxazine (obtained by reacting6,7-dimethoxy 9 (1' L arabityl) isoalloxazine with periodic acid), 6,7dimethoxy 9 [[3-hydroxyethy11- isoalloxazine is obtained.

PREPARATION 7.-6,7-TE'I'RAMETHYLENE-9-[B-HYDROXY- nTHYL]-IsOALLoxA2.u-IE

Following the procedure described in Preparation 1 except for thesubstitution of 6,7-dimethyl-9-formylmethylisoa loxazine by 32.8 gramsof 6,7-tetramethylene- 9-formylmethylisoalloxazine (obtained by reacting6,7- tetramethylene 9 (1' D arabityl) isoalloxazine [Kuhrn Ber., 70,1302, 1937] with periodic acid), 6,7- tetramethylene 9 [,8 hydroxyethyl]isoalloxazine is obtained.

PREPARATION 8.-6-ME'I'HYL-7-AMINO-9-[fi-HYDROXY- ETHYL]-IsOALLoxAzrNEFollowing the procedure described in Preparation 1 except for thesubstitution of 6,7dimethyl-9-forrnyl methylisoalloxazine by 28.5 gramsof 6-methyl-7-amino- 9-formylmethylisoalloxazine' (obtained by reacting6- methyl 7 amino 9 (1' D arabityl) isoalloxazine [Nishida, Rpts. Sci.Res. Inst., Japan, 25, 323, 1949] with periodic acid), 6 methyl 7 amino9 [B- hydroxyethyl]-isoalloxazine is Obtained.

PREPARATION 9.-6,7-DIMETHYL9['y-HYDROXYPROPYL] ISOALLOXAZINE PREPARATION10.-6,7-DMETHYL-9-[5-HYDROXYBUTYL1- IsoALLOxAzINE Following theprocedure described in Preparation 1 except for the substitution of6,7-dimethyl-9-formylmethylisoalloxazine by 31.2 grams of6,7-dimethyl-9-['y-formylpropyl]-isoalloxazine (obtained by reacting6,7-dimethyl- 9-(4',5'-dihydroxyamyl)-isoalloxazine with periodic acid),6,7-dimethyl 9 [fi-hydroxybutyl]-isoalloxazine is obtained.

PREPARATION 1 1.-6,7-DIETHYL-9-[fi-HYDROXYETHYL1- IsoALLoxAzrNEFollowing the procedure described in Preparation 1 except for thesubstitution of 6,7-dimethyl-9-formylmethylisoalloxazine by 31.2 gramsof 6,7-diethyl-9- formylmethylisoalloxazine (obtained by reacting6,7-diethyl 9 (1'-D-ribityl) isoalloxazine iLambooy, J. Am. Chem. Soc,72, 5225, 1950] with periodic acid), 6,7-diethyl-9- [fl-hydroxyethyl]-isoalloxazine is obtained.

PREPARATION l2.6-\/.lETHOXY-7-AMIINO-9-[fi-HYDROXY-ETHYLII-ISOALLOXAZINE Following the procedure described in Preparation 1except for the substitution of 6,7-dimethyl-9-formylmethylisoalloxazineby 30.1 grams of 6-methoxy-7-amino-9 formylmethylisoalloxazine (obtainedby reacting 6-methoxy 7 amino 9 (1 D ribityl)-isoalloxazine withperiodic acid), 6-methoxy-7-aminO-9[fi-hydroxyethyll'r isoalloxazine isobtained.

PREPARATION 13.-5,6,7,8-TE'IRAMETHYL-9-[fi-HYDROXY- ETHYL1-ISOALLOXA11NEFollowing the procedure described in Preparation 1 ex cept for thesubstitution of 6,7-dimethyl-9-formylmethylisoalloxazine by 31.2 gramsof 5,6,7,8-tetramethyl-9- formylmethylisoalloxazine (obtained byreacting 5,'6,7,8- tetramethyl-9-(1-L-arabityl)-isoalloxazine withperiodic ads-.729

' Example 1.6,7-dimethyl-9-is0all0xazineethyl acetate Fifty millilitersof dry pyridine is mixed with 2.9 grams (0.01 mole) of6,7-dimethy-9-[fl-hydroxyethyll-isoalloxazine (Preparation 1). Anexcess, 1.56 grams (0.02 mole), of acetyl chloride is added, withstirring, to the mixture while it is cooled in an ice bath. The mixtureis heated under reflux until all of the6,7-dimethyl-9-[B-hydroxyethyll-isoalloxazine is dissolved, at whichtime the reaction'is substantially complete. The pyridine solution iscooled, diluted with twenty milliliters of ethanol, and then-stirredvigorously. The solution is concentrated in vacuo to an oil which isdissolved in 25 milliliters of methanol. On adding 200 milliliters ofether, a precipitate is obtained which is then dried. The substantiallypure 6,7-dimethyl-9-isoalloxazineethyl acetate thus obtained meltsbetween 228 and 232 degrees uncorrected.

Analysis.Calculated for c,,H,,N,o,=

Calculated Found 58. 5 58. 4 F 4. 9 4. 9 N 17. 1 16. 7 CHzCO 13. 1 14. 3

Using acetic anhydride as the acylating agent instead of acetyl chlorideas described above, 6,7-dimethyl-9-isoalloxazineethyl acetate isprepared in the following manner:

A mixture containing 28.6 grams of 6,7-dimethyl-9-[B-hydroxyethyl]-isoalloxazine (Preparation 1), 200 milliliters of aceticanhydride and 400 milliliters of pyridine is heated under reflux for onehour. At the end of this period of time, the dark solution thus obtainedis filtered, while hot, through a Buchner funnel thereby removingunacetylated materials. On evaporating the filtrate to dryness, ablackish-green solid is obtained. The crude material is triturated withfifty milliliters of ethanol and the mixture is then filtered. The solidmaterial is triturated again with fifty milliliters of ethanol and themixture is filtered. The partially purified material is washed with amixture of fifty milliliters of ethanol and fifty milliliters of etherfollowed by another wash with 100 milliliters of ether and the productis then dried. Substantially pure 6,7-dimethyl-9-isoalloxazineethylacetate is thus obtained melting between 228 and 232 degrees centigrade.

. .iExample 2.-6,7-dimethyl-9-isoall0xazineethyl dihydrogen phosphate To122.6 grams (0.8 mole) of phosphoryl chloride is added slowly,accompanied by stirring and cooling, 28.0 grams (1.6 moles) of water.The mixture is agitated until the evolution of hydrogen chloride appearscomplete at which time the solution is allowed to stand overnight.Stirring is resumed until the evolution of hydrogen chloride gas ceases.

A mixture of fifteen milliliters of chlorophosphoric acid [(HO) POCl]thus obtained and 5.0 grams of 6,7- dimethyl-Q-[fi-hydroxyethyllisoalloxazine (Preparation 1) is stirred until solution is complete (24to 40 hours). Protection from light is maintained throughout thereaction. The solution is cooled in an ice-bath and theunreacted-chlorophosphoric acid is destroyed by reacting it with sixtymilliliters of methanol. On the addition of a mixture containing eightymilliliters of ether and eighty milliliters of hexane, a blackish, gummyresidue is obtained. The mass is dissolved in 200 milliliters of coldmethanol and 300 milliliters of ether is added thereto. A brownish-greensolid is obtained. The solid is removed by centrifugation andredissolved in 200 milliliters of cold methanol. A brownish precipitateis obtained on the addition of' 3,00 milliliters of ether. The mixtureis centrifuged, the solid material is separated, washed thorough lywith'ether and dried at a temperature of sixty degrees centigra'del' The 6,7-dimethyl-9-isoalloxazineethyl dihydrogen phosphate thus obtainedmelts between 210 and.

Example 3.6,7-dimethyl-9-is0alloxazineethyl hydrogen sulfate To 135grams of sulfuryl chloride in a 300 milliliter Erlenmeyer flask cooledin an ice-bath, is added, with stirring, eighteen grams of water; aviolent reaction occurs. The mixture is allowed to stand overnight.

Ten milliliters of chlorosulfonic (HOSO CI) acid thus obtained is mixedwith five grams of 6,7-dimethyl- 9- [B-hydroxyethyl]-isoalloxazine(Preparation 1) and the resulting mixture is stirred, while protectedfrom light. After standing for a period of 24 hours, the syrupy mass iscooled and 65 milliliters of methanol is added followed by the additionof 200 milliliters of ether to the resulting solution. The precipitatethus formed is removed by centrifugation and the solid material isdissolved in 200 milliliters of cold methanol. Three hundred millilitersof ether is added to the methanolic solution thereby forming aprecipitate which is redissolved in milliliters of methanol. On theaddition of 200 milliliters of ether to the solution, a yellow-orangesolid is obtained. The solid material is removed by centrifugation,washed thoroughly with ether and dried at a temperature of sixty degreescentigrade. The solid 6,7-dimethyl-9-isoalloxazine ethyl hydrogensulfate thus obtained melts between 223 and 225 degrees Centigrade,uncorrected.

Similarly, by reacting sulfuryl chloride With 6,7-dimethyl-9 9hydroxyethyl] isoalloxazine, di [6,7- dimethyl-9-isoalloxazineethyl]sulfate is obtained.

Example 4.6,7-dimethyl-9-is0all0xazineethyl propionate Fifty millilitersof dry pyridine is mixed with 2.9 grams (0.01 mole) of6,7-dimethyl-9-[fl-hydroxyethyll-isoalloxazine (Preparation 1). Anexcess, 2.3 grams (0.025 mole), of propionyl chloride is added, withstirring, to the mixture, while cooling. The mixture is refluxed untilthe 6,7-dimethyl-9- ,B-hydroxyethyll isoalloxazine dissolves, at whichtime the reaction is substantially complete. The pyridine solution isdiluted with twenty milliliters of methanol, the solution is stirredvigorously and concentrated in vacuo to an oil. The resulting mass isthen dissolved in 25 milliliters of ethanol. On the addition of 200milliliters of ether, a precipitate is obtained. The solid material isdried and recrystallized to obtain substantially pure6,7-dimethyl-9-isoalloxazineethyl propionate.

Example 5 .6,7-dimethyl-9-isoall0xazineethyl hydrogen succinate Amixture of 3.8 grams of 6,7-dimethyl-9-[p-hydroxyethyl]-isoalloxazine(Preparation 1), 3.0 grams of succinic anhydride and 100 milliliters ofpyridine is refluxed for one hour. The solution is cooled and 200milliliters of ether is added thereto. The precipitate thus formed isdissolved in fifty milliliters of methanol and, on the addition of 200milliliters of ether, a precipitate is obtained. The precipitate isredissolved in fifty milliliters of methanol and on the addition of 200milliliters of ether, a precipitate is once again obtained. The solidmaterial is washed successively with three 100-milliliter portions ofhot acetone, fifty milliliters of ether and dried. The substantiallypure, 6,7-dimethyl-9-isoalloxazineethyl hydrogen succinatethus obtainedmelts between 227 and 228 degrees Centigrade, uncorrected.

' ethyl] -isoal1oxazine. (Preparation S mflafluy a tin sl f c n l h iise w h 6,7:di? i' fiy i h' lli a .al le q iie d z fiflidi i i yl9-isoalloxazineethy1] 'succinate isobt'ained. f". .i' if Mixedsuecinatei esters of, 6,7dimethyl- 9;iiiflly'fdroxye'thyllisoalloxa'zine are obtained by treating succinic'an hydride with an'alkanol such as methanolfethanoli. b11- tanol, or the like, toform the,corresponding alltyl hydrogn succinate' such as methyl hydrogensuccinate, ethyl hydrogen, succinate butyl hydrogen succinate, or thelik reacting the resulting-compound with thionyl chloride, and thenreacting thec onjpound thus obtained with 6,7-dimetliyI '9 [flliydroxyethyll-isoalloxazine to obtain he t cx e rw c 2 i ;7- methy1-isoall xa inee alkyl succinate such as16,7-dimethyl-9-isoalloxazineethyl' '386 milligrams'of6,7-dimethyl9-isoalloxazineethyl hydreg n succin'a'te (Example "5 is dissolved in'9.0"-' iniliters of' Oil Nfs'odiiimfhydiroxide and 'the'resultih'g m,tionisfiltered. 'Ihe filtrate is freeze-dried.' There is obtained 400milligramsof the 's'odium 'salt of 6,7 -di methyl-9-isoalloxazineethylsuccinate. Anaqueous: solutiloniof hepmaucrpessesses a'pH'of about 'ZO.

Eqcanzpile 7.-'-I? 2 tassiz m 6,7-dimethyl-9:isoalloxazineethylsuccinate ceptfor the replacement'of soditini'hydroxide hypo"- o 19': m eha eteen r n a om saute-2:99am such as sodium 6,7-dimethyl 9isoalloxazineethyl phth alate, pota'ssium6,7-dirnethyl-9-isoalloxazineethyl phthalate,. calcium6,7-dimethylr9-isoalloxazineethyl 'phthalate, sodium6,7-dimethyl-9-isoalloxazineethyl glutamate, tassium6,7-dimethyl-9-isoalloxazineethyl glutamate,- ital cium 6,7dimethyl-9-isoalloxazineethyl glutamate, sodium6,7-dimethyl-9-isoalloxazineethyl aspartate; potassiunjfifidimethy1-9-isoalloxazineethyl aspartate; calcium 6,7 dimethyl-9-isoalloxazineethyl 'aspartate, sodium: fifl dimethyI-9-isoalloxazineethyl adipate, potassium 6,1-di5'methyl-9-isoalloxazineethyl adipateysodium 6,7-diinethyla9-isoalloxazineethyl itaconate, potassium- 6,7'dimethyl -9isoalloxazineethyl' itaconate, sodium GJ-dimethyI-Q-iso alloxazineethylcitraconate, potassium 6,'7- dimethyl 9-i3o-' alloxazineethyl'citraconate,and the like;

Example I0.6,7-dimethyl-9 isqallqqcazineegryl. l g gqgte A mixture of286. milligrams (0.001 mole otim-di, methyl9-[p-hydroxyethyl]-isoalloxazine (Preparation 1), 141 milligrams (0.001mole).o:henzoyl chloride-audible milliliters oi y ous. Pyri ine. s. heatd on. esteembath for one hour. A brownishsolution-is formed. pyridine isremoved by distillation' andthe r'esidue isl extracted with water andalcohol, On removaltof the. solvents by evaporation,6,7-dimethyla9-isoalloxazineeg yl benzoate is obtained as. a brown solid5 34 68 egre s n igrade infill??? a r 7' 3 Following the proceduredescribed in Example 6 ex ta'ssium hydroxide, there is obtained 400milligrams. of r the" potassium salt of 6,7-dimethyl 9isoalloxazineethyl succinate.

Example 8.-Calcium 6,7-dimethyl-Q-isoalloxuzineethyl succinate.

' Following the procedure described in Example 6 except for thereplacement of sodium hydroxide Bycalcium hydroxidefthere is obtained400 milligrams of the calcium salt of 6,7-dimethyl-9 isoalloxazinethylsuccinate,

The above prepared sodium, potassium and calcium salts; of6,7-dimethyl-9-istialloxazineethyl succinate are soluble in water and inbufiers of a pH, rangbetween about 7.0 and about 8.0 to the extent offour to ten percentweight by volume. These salts are also readilysoluble in five percent, glucose and parenteral infusion Example9-.6,Z-dimethyl-Q-imdlloxqzineethyl V hydrogen maleate A mixture of 3.8grams of 6,7-dirnethyl-9- [ti-hydroxy- 1), 3.0 grams of maleic anhydrideand 100 milliliters of The's olution iscooled androfn the addition oi200 milliliters of ether, a precipitate is formed. Ifhe precipitate. isredissolved in fifty milliliters of methanol and on the addition of 2jQ0milliliters of ethena' precipitate is once again formed. The solidmaterial is washed successively with three 100-milliliter portions ofhotacetonejfifty milliliters of etherand dried. There'- is obtainedsubstantially pure 6,7-dimethylf9-isoalloxazineethyl. hydrogen maleate.On reacting the 6,7-dimethy1-9-isoalloxazineethylY hy dliogen malea'tethus obtained with a suitable alkali metal base or'alkaline earth'metalbase 'such as, sodium hyd oxide, potassium hydroxide, calcium hydroxide,and the l k (u i q he nr re se forth i E amp e h ir s ii s tis bta d h.d nm fifiiz methyl 9l iso alloxazineethyl maleate, -potassiu'm .6,7-dithyI-Q-isoaIlQxaZineethyI maleate, calcium 6,7;di-i

'l-9 "and: zinlhill maleaifandl'the like.

i alklijm'et lfanid lk line. e artlifme'tal'salts ofisoalloxa'zi'rie'alliyl' esters eriyed'from polyb i pyridine is refluxedfor brown solid material. Th e solid'materialisiwashed with 2+ieiesszieeti f itilielitlialea;' y ih ke Example 11.-6 7-dimethyl-9isoizlloxazir eethy1 laurate A mixture oi 500 milligrams of v6,71-dim rhstr,sgh r drpxyethyll isoalloxazine (Preparation 1 and 5,0.m liters oflau'royl chloride is stirred for two hours and w allowed to stand for anadditional period of ftwo ho On the addition of an excess quantity ofether, a p cipitate is formed. The solid material isfremovedj-bycentrifuging, redissolved in cold methanolyreprecipitatedl V by theaddition of ether, centrifuged and 'air dried, 6, rdimethyl-9-isoalloxazineethyl laurate' islobtaine d me between 7223 and225 degrees centigrade, uncorrected; Etdmlfl .-6 7- im thyla s t z n ehyl dmit ye A mixture of 5.0 milliliters of palmitoyl chloridean'd 500milligrams of 6,7-dimethyl-9-[B-hydroiyethylldsm alloxazine(Preparation 1) is :stirred for'nineteerr hours while protected fromlight. Eighty millilitersofizmethahnk is added to the mixture. Theinsoluble, unreacted 6,7-dimethyl-9: lfirhydroxyethyll -isoalloxazine'is removedfrom the solution by filtration. An excess quantity ofetherisadded to the, motherliquor thereby forming ayellpwisb V Exa pdegrees centigrade,"uncorrected.

' Similarly, other esters of- 6,7-dimethyl-9-[p-hydroxyethyllisoallo'xazine. are prepared such. as'6,7-dimethyl-9-e.-.isoalloxazineethyl salicylate, 6,7-dimethyl-9risoalloxazinezethyl-hydrogen phthalate, di [6,7 dimethyl9;- isoal; loxazineethyl]phthalate, mixed phthalate im @11 a y r ethy s a1l9Xe i9 h.-. emethyl-9Tisoalloxaaineethyl methyl plithalate,

13 Example 14.7-methyl-9-is0alloxazineethyl acetate Following theprocedure described in Example 1 except for the substitution of6,7-dimethyl-9-[,B-hydroxyethyll-isoalloxazine by 2.7 grams of7-methyl-9-[B-hydroxyethyl]-isoalloxaziue (Preparation 4), 7-methyl-9-isoalloxazineethyl acetate is obtained.

Example 15.7-methyl-9-is0all0xazineethyl hydrogen succinate Followingthe procedure described in Example 5 except for the substitution of6,7-dimethyl-9-[B-hydroxyethyll-isoalloxazine by 3.0 grams of7-methyl-9-[fi-hydroxyethyll-isoalloxazine (Preparation 4), 7-methyl-9-[,B-hydroxyethyl]-isoalloxazineethyl hydrogen succinate is obtained.

Similarly, by reacting succinyl chloride with 7-methyl-9-[,8-hydroxyethyl]-isoalloxazine, di-[7-methyl-9 isoaloxazineethyll-succinate is obtained.

Mixed succinate esters of 7-methyl-9-[fi-hydroxyethyl]- isoalloxazineare obtained by treating succinic anhydride with an alkanol such asmethanol, ethanol, butanol, and the like, to form the correspondingalkyl hydrogen succinate such as methyl hydrogen succinate, ethylhydrogen succinate, butyl hydrogen succinate, and the like, reacting theresulting compound with thionyl chloride, and then reacting the compoundthus obtained with 7-methyl-9- Ldhydroxyethyl]-isoalloxazine to obtainthe corresponding 7-methyl-9-isoalloxazineethyl alkyl succinate such as7-methyl-9-isoalloxazineethyl methyl succinate, 7-methyl-9-isoalloxazineethyl ethyl succinate, 7-methyl-9-isoal loxazineethylbutyl succinate, and the like.

Following the procedure described in Example 6 except for thesubstitution of 6,7-dimethyl-9-isoalloxazineethyl hydrogen succinate by372 milligrams of 7-methyl-9- isoalloxazineethyl hydrogen succinate,there is obtained sodium 7-methyl-9-isoalloxazineethyl succinate.

Similiarly, on reacting 7-methyl-9-isoalloxazineethyl hydrogen succinatewith potassium hydroxide, calcium hydroxide, or the like, thecorresponding salt is obtained such as potassium7-methyl-9-isoalloxazineethyl succinate, calcium7-methyl-9-isoalloxazineethyl succinate, and the like.

Example 16.7-methyl-9-isoalloxazineethyl dihydrogen phosphate Followingthe procedure described in Example 2 except for the substitution of6,7-dimethyl-9-[fi hydroxyethyll-isoalloxazine by 5.0 grams of7-methyl-9-[j3-hydroxyethyl]-isoalloxazine (Preparation 4), 7-methyl-9-isoalloxazineethyl dihydrogen phosphate is obtained.

Similarly, by reacting 7-methyl-9- [fl-hydroxyethylJ-isoalloxazine withdichlorophosphoric acid, the correspondingdi-[7-methyl-9-isoalloxazineethyl] hydrogen phosphate is obtained.

By reacting phosphoryl chloride with7-methyl-9-[fihydroxyethyl]-isoalloxazine, tri [7 methyl 9isoalloxazineethyl] phosphate is obtained.

Similarly, other esters of 7-methyl-9-ifl-hydroxyethyllisoalloxazine areprepared such as 7-methyl-9-isoalloxazine hydrogen sulfate,di-[7-methyl-9-isoalloxazineethy1l sulfate,7-methyl-9-isoalloxazineethyl benzoate, 7-methyl- 9-isoalloxazineethylpropionate, 7-methyl-9-isoalloxazine1 ethyl hydrogen maleate,7-methyl-9-isoalloxazineethyl hydrogen phthalate, 7-methyl-9isoalloxazineethyl hydrogen glutamate, 7-methyl-9-isoalloxazineethylhydrogen aspartate, 7-rnethyl-9-isoalloxazineethyl hydrogen glutarate,7- methyl-9-isoalloxazineethyl hydrogen adipate, 7-methyl-9-isoalloxazineethyl hydrogen itaconate, and the like, in-' cluding thealkali metal and'alkaline'earth metal salts thereof.

Example 1 7.6-ethyl-7-methy'l-9-isoalloxazineethyl acetate Following theprocedure described in. Example l vexcept for the substitution of6,7-dimethyl-9-[p-hydroxyethyllaaaaae 14 isoalloxaz ine by 3.0 grams of6-ethyl-7-methyl-9-[ S-hydroxyethyl]-isoalloxazine (Preparation 2),6-ethy1-7- methyl-9-isoalloxazineethyl acetate is obtained.

Example 1 8.-6-ethyl-7-methyl-9-isoalloxazineethyl dihydrogen phosphateFollowing the procedure described in Example 2 except for thesubstitution of 6,7-dimethyl-9-[fi-hydroxyethyl]- isoalloxazine by 5.0grams of 6-ethyl-7-methyl-9-[,6-hydroxyethyl]-isoalloxazine (Preparation2), 6-ethyl-7- methyl-9-isoalloxazineethyl dihydrogen phosphate isobtained.

By reacting dichlorophosphoric acid with 6-ethyl-7-methyl-9-[fi-hydroxyethyl]isoalloxazine, the correspondingdi-i6-ethyl-7-methyl-9-isoalloxazineetl1yl] hydrogen phosphate isobtained.

Similarly, by reacting phosphoryl chloride with 6-ethyl- 7-methyl-9-fi-hydroxyethyl -isoalloxazine, tri- [6-ethy1-7-methyl-9-isoalloxazineethyll phosphate is obtained.

Example 19.6-ethyl-7-methyl-9-is0alloxazineethyl hydrogen succinateFollowing the procedure described in Example 5 except for thesubstitution of 6,7-dimethyl-9-[fi-hydroxyethyuisoalloxazine by 4.0grams of 6-ethyl-7-methyl-9-[fi-hydroxyethyll-isoalloxazine (Preparation2), 6-ethyl-7- methyl-9-isoalloxazineethyl hydrogen succinate isobtained.

By reacting succinyl chloride with 6-ethyl-7-methyl-9- ifi-hydroxyethyl]isoalloxazine, di-[6-ethyl 7-methyl-9- isoalloxazineethyl] succinate isobtained.

Mixed succinate esters of6-ethyl-7-rnethyl-9-[p-hydroxyethyllisoalloxazine are obtained bytreating succinic anhydride with an alkanol such as methanol, ethanol,butanol, and the like, to form the corresponding alkyl hydrogensuccinate such as methyl hydrogen succinate, ethyl hydrogen succinate,butyl hydrogen succinate, and the like, reacting the resulting compoundwith thionyl chloride, and then reacting the compound thus obtained with6-ethyl-7-methyl-9-[B-hydroxyethyl]-isoall0xazine to obtain thecorresponding 6-ethyl-7-methyl-9-isoalloxazineethyl methyl succinate,6-ethyl-7-methyl-9-is0- alloxazineethyl ethyl succinate,6-ethyl-7-methyl-9-isoalloxazineethyl butyl succinate, and the like.

Following the procedure described in Example 6 except for thesubstitution of 6,7-dimethyl-9-isoalloxazineethyl hydrogen succinate by400 milligrams of 6-ethyl-7-tnethyl- 9-isoalloxazineethyl hydrogensuccinate, there is obtained the sodium salt of6-ethyl-7-methyl-9-isoalloxazineethyl hydrogen succinate.

In a similar manner, the potassium and calcium salts of6-ethyl-7-met'nyl-9-isoalloxazineethyl succinate are obtained byreacting 6-ethyl-7methyl-9-isoalloxazineethyl alloxazineethyl hydrogenaspartate, 6-ethyl-7-methyl-9-is0- alloxazineethyl hydrogen glutarate,6-ethyl-7-methyl 9-is0- alloxazineethyl hydrogen adipate,6-ethyl-7-methyl-9-isoalloxazineethyl hydrogen itaconate, and the like,including the alkali metal and alkaline earth metal salts thereof.

Example 20.-6,7-dichlor0-9-is0alloxazineethyl acetate Following theprocedure described in Example 1 except for the substitution of6,7-dimethyl-9-[B-hydroxyethyllisoalloxazine by 3.3 grams of6,7-dichloro-9-[B-hydroxyethyll-isoalloxazine (Preparation 5),.6,7-dichloro9-isoalloxazineethyl acetate is obtained.

, drogen succinateg, V

V l lgcgzmpl'e 21.:6,7-dichlbror9aisoalloxazineethyl" dihydrogenphosphate l 4 Following theprocedure described in Example 2 except forthe substitution of 6,7-dirnethyl-9-[fl-hydroxyethyllisoalloxazine by5.0 grams of 6,7-dichloro-9-[fl-hyclroxyethyll-isoalloxazine(Preparation 5), 6,7-dichloro-9-isoalloxazine'ethyl dihydrogen phosphateis obtained. By reacting dichlorophosphoric acid with 6,'7-dichloro-9-.[B-hydroxyethyl]-isoalloxazine, the corresponding di-[6,7;dichloro-9-isoalloxazineethyl] hydrogen phosphate is obtained.- Q Ia a Similarly. by reacting phosphoryl chloride with 6,7-dichloro-9- phydroxyethyll -isoalloxazine, tri [6,7-dichlor0- 9-isoalloxaz'ineethyl1phosphate is obtained.

Example 22 .6,7-dich[oroQ-isoallqxazinerhyl hydrogen succinateFollowingthe procedure described'in Examplei except for the substitution.of 6,7-dir'nethyle9![pehydroxyethyl] isoalloxazine. .by-4.4- grams of6,7-dichloro-9- [phhydroxyethyll-isoalloxazine. (Preparation 5.),- 6,7-dichl0'ro-9-'iso al loxazineethyl hydrogen succinate is obtained.'Similarly, by-reacting succinyl' chloride with 6,7-dichloro-9;lfp-hydroxyethyll isoalloxazine; di:[6,7-dichlor0e 9,-isoalloxazineethyl1' succinate is obtained; V

vMixed succina te' esters of 6,7-dichloro-9-[prhydroxythyllisoalloxazine are obtained by treating succinic an h drid with. n. kausuch eth noh ethano b anQ1ran -th. i to f rm he c r sponding alkylhydrogen su ccinate' such as; methyl hydrogen succinate, ethyl hydrogensuccinate, 'butylf hydrogen succinate, and theililge, reacting theresulting compound with thionyl' V chloride, and then reacting thecompound thus obtained with V 6,7dichloro-9-[B-hydroxyethyl]5isoalloxazine to obtain the corresponding;6,7-dichloro-9-isoalloxazine-. ethyl alkyl su'ccinate such as6,7-dichloro9-isoalloxazine:' ethyl" methyl 'succinate', 6,7-dichloro-9risoalloxaiineethyl ethyl .succinate,6,7-dichloro-9-isoalloxazineethyl 'butyl snccinate, and the like I aFollowing. the procedure'described in Example except for" thereplacement of .6,7:dimethyl-9-isoalloxazineethyl hydrogen succinate by427 milligrams of 6,7 -ciichloro-9-v gen glutar'ate, 6,7-dichloro-9isoalloxaziueethyl hydrogen P E; 6,7-dichl0ro-9-isoalloxazineethyl h droe coma; and the like including the alkali: metafand, alkaline earthmetal-salts thereof: a

Example 23 .t i ritethyl-7- amino-9-isballqacazifiee thyi acetate.Eollowing theprocedure-described .Example. .1 ex; ceptfprthejsubs-titution of pyridine by; acetic acid and,

alloxazine. by 2.9. grams .of fi-methyl-7-amino-9-[phydroxyethylJ-isoalloxazine hydrochloride (obtained byfreacting6-methyl-7 amino-9- ['fi-hydroxyethyl] -isoalloxazine [Preparation -8]with alcoholic hydrogen chloride), 6 methyl-7-amiuo-9-isoalloxazineethylacetate hydrochloride is obtained. This is converted to6-methyl-7-an1ino-9- isoalloxazineethyl acetate by treatment with analkali.

or amine base.

Example 24.6-methyl-7-amino-9-isoalloxazineethyl propionate Followingthe procedure described in Example 4 except for the substitution ofpyridine by propionic' acid and the replacement of 6,7-dimethyl-9-[fi-hydroxyethyllisoalloxazine' by 5.0 grams of6-rr1ethyl-7-amino-9.-[fi3 hydroxyethyl]-isoalloxazine hydrochloride(obtained by reacting 6 -methyle7-amino-9- [,8-hydroxyethyl]isoalloxa-'zine [Preparation 8] with alcoholic hydrogen chloride),

6-methyl-7-amino-9-isoalloxazineethyl proprionate hydro-- chloride isobtained. This is converted to 6-methyl-7- amino-9-isoalloxa'zineethylpropionate by treatment with an alkali or' amine baser V Example25.5,7-diethyl-9-isoalloxazineethyl acetate Following theproceduredescribed in. Example 1 except for the, substitution of6,7-dimethyl-9-EB-hydroxyethyllisoalloxazine by 3.1 grams of6,7-diethyl-9-[fi-hydroxyethyllrisoalloxazine (Preparation 11),6,7-diethyl-9-isoalloxazineethylacetateis obtained.

Exzmiple' 26. 6,7-dietiiyI-9 isoallaxazineethyl propion ate Following.the procedure described in Example'4 ex-' cept for thessubstitution' of6,7-dimethyl-9- [fi-hydroxyethyH-isoalloxazirie. by. 3.1 grams of6,7-diethyl -9-[B- hydroxyethyl]-isoalloxazine (Preparation 11), 6,7-di-' ethyl-9-isoalloxazineethyl propionate is obtained;

' Similarly, other esters of 6,7-diethyl-9-[B-hydroxyethyll-isoalloxazine are prepared such as 6,7.-diethyl-9-i soalloxazineethylhydrogen sulfate, di-[6,7-diethyl-9-isoalloxazineethyl] sulfate,6,7-diethyl-9-isoalloxaaineethyl benzoate, 6,7diethyl+9-isoalloxazineethyl laurate, 6,7-diethyl-9-is oalloxazineethyldihydrogen phosphate, di- [6,75

diethyl-9aisoalloxazineethyl] hydrogen phosphate;v tri-v.

[6,7 diethyl-9-isoalloxazineethyl1 phosphate,"and the like; Example,27.-6,7-dimethyl-9-isoalloxazinepropyl acetate Following the proceduredescribedin Example l except-for:the-substitution of 6,7-dimethyl-9[fi-hydroxyethyl l-isoall'oxazine by- 320' grams of 6,7-dirnethyla9-I'-hy droxypropyll' isoalloxazine (Preparation 9), 6,7-dimethyl- 9is'oalloxazinepropyl acetate is obtained. i

Example.- 28.6,-7 -dimethyl-9-is0alloxuzinepropyl di hydrogen phosphatej V Following theprocedure describedjin Example 2L'ex-. cept'forthe'sub'stitution of 6,7-dimethy1 '9 [fi-hydroxy ethyll-isoalloxazine by5.0 grams of 6 ,7-dimethyl-9eP hydroxypropyl'l-isoalloxazine(Preparation 9.) 6,7 di= methyl-9.-isoalloxazinepropyl dihydrogenphosphate is obtained.

By reacting.dichlorophosphoric acid withyl-9-[ry-hydroxypropyl]-isoalloxazine, the corresponding" di [6,7dimethyl9-isoalloxazinepropyl1i hydrogen 1 phosphate i'sobtained. a'Similarly, by reacting phosphoryl chloride with 6,7-.dime.thyl-9-.['y-hydroxypropyll isoalloxazine,vtri--[6,7-dimethyl-9-iso-alloxazinepropyl] phosphate is. obtained.

'Example 29.'6,7-iiimethyl-9-isoullcxizzinepropyl'hy V '7 arogensuccinate Following-the procedure described in Example iexcept for thesubstitution of'6i7-d methyl-9-[fl-hydroxyethyll-isoalloxazine, by..4.0,-. grams. of; 6,7:din1ethyl-9- ['-hydroxypropyll isoalloxaziue(Preparation 9),; 6,7-

dimethyl-9-isoalloxazinepropyl hydrogen succinate is obtained.

Similarly, by reacting succinyl chloride with 6,7-dimethyl-9['y-hydroxypropyl] isoalloxazine,di-[6,7-dimethyl-9-isoalloxazinepropyll succinate is obtained.

Mixed succinate esters of 6,7-dimethyl-9-[ -hydroxypropylJ-isoalloxazineare obtained by treating succinic anhydride with an alkanol such asmethanol, ethanol, butanol, and the like, to form the correspondingalkyl hydrogen succinate, such as methyl hydrogen succinate, ethylhydrogen succinate, butyl hydrogen succinate, and the like, reacting theresulting compound with thionyl chloride, and then reacting the compoundthus obtained with 6,7-dimethyl-9-['y-hydroxypropyl]-isoalloxazine toobtain the corresponding 6,7-dimethyl-9-isoalloxazinepropyl alkylsuccinate such as 6,7-dimethyl-9-isoalloxazine propyl methyl succinate,6,7-din'1ethyl-9-isoalloxazinepropyl ethyl succinate,6,7-dirnethyl-9-isoalloxazinepropyl butyl succinate, and the like.

Following the procedure described in Example 6 except for thesubstitution of 6,7-dimethyl-9-isoalloxazineethyl hydrogen succinate by400 milligrams of 6,7-dimethyl-9-isoalloxazinepropyl hydrogen succinate,there is obtained the sodium salt of 6,7-dimethyl-9-isoalloxazinepropylsuccinate.

In a similar manner, on reacting 6,7-dimethyl-9-isoallox-azinepropylhydrogen succinate with potassium hydroxide or calcium hydroxide, thereis obtained the corresponding potassium or calcium salt of6,7-dimethyl-9- isoalloxazinepropyl succinate.

In the same manner, other esters of6,7-dimethyl-9-[vhydroxypropyl]-isoalloxazine are prepared such as 6,7-dimethyl-9-isoalloxazinepropyl propionate, 6,7-dimethyl-9-isoalloxazinepropyl hydrogen sulfate, di-[6,7-dimethyl-9-isoalloxam'nepropyl] sulfate, 6,7-dimethyl-9-isoalloxa- 9 zinepropylbenzoate, 6,7-dimethyl-9-isoalloxazinepropyl myristate,6,7-dimethyl-9-isoalloxazinepropyl hydrogen maleate, 6,7 dimethyl 9isoalloxazinepropyl hydrogen glutamate, 6,7 dimethyl 9isoalloxazinepropyl hydrogen aspartate,6,7-dimethyl-9-isoalloxazinepropyl hydrogen glutarate,6,7-dimethyl-9-isoalloxazinepropyl hydrogen adipate,6,7-dimethyl-9-isoalloxazinepropyl hydrogen itaconate, and the like,including alkali metal and alkaline earth metal salts thereof.

Example 30.-6,7-dimethoxy-Q-isoalloxazineethyl acetate Following theprocedure described in Example 1 except for the substitution of6,7-dimethyl-9-[pl-hydroxyethyll-isoalloxazine by 31.8 grams of6,7-dimethoxy-9- [fl-hydroxyethyl]-isoalloxazine (Preparation 6),6,7-dimethoxy-9-isoalloxazineethyl acetate is obtained.

Example 31.6,7-tetramethylene-9-isoalloxazineethyl propionate Example32.-6,7-dibrom-9-is0all0xazineethyl acetate Following the proceduredescribed in Example 1 except for the substitution of6,7-dimethyl-9-[fi-hydroxyethyll-isoalloxazine by 41.6 grams of6.7-dibrorno9 [fi-hydroxyethyl]-isoalloxazine (Preparation 14), 6,7-dibromo-9-isoalloxazineethyl acetate is obtained.

Example 33.-5-meth0xy-6-amina-9-is0alloxazineethyl propionate Followingthe procedure described in Example 4 except for the substitution ofpyridine by propionic acid and the replacement of 6,7-dimethyl-9-[fi-hydroxyethyllisoalloxazine by 30.3 grams of5-methoxy-6-arnino-9-[B-' hydroxyethyll-isoalloxazine' hydrochloride"(obtained by reacting5-methoxy-6-amino-9-[fi-hydroxyethyl]-isoalloxazine [Preparation 15]with alcoholic hydrogen chloride),5-methoxy-6-amino-9-isoalloxazineethyl propionate hydrochloride isobtained. This is converted to S-methoxy-6-amino 9-isoalloxazineethylpropionate by treatment with an alkali or amine base.

Example 34.-5,6-dimethyl-9-is0all0xazineethyl acetate Following theprocedure described in Example 1 except for the substitution of6,7-dimethyl-9-[fi-hydroxyethyllisoalloxazine by 28.6 grams of5,6-dimethyl-9-[B-hydroxyethylJ-isoalloxazine (Preparation 3),5,6-dimethyl- 9-isoalloxazineethyl acetate is obtained.

Example 35 .6,7-alimethyl-Q-isoalloxazinebutyl acetate Following theprocedure described in Example 1 ex cept for the substitution of6,7-dimethyl-9-[,B-hydroxyethyll-isoalloxazine by 31.4 grams of6,7-dimethyl-9- [B-hydroxybutyl]-isoalloxazine (Preparation 10),6,7-dimethyl-9-isoalloxazinebutyl acetate is obtained.

Example 36.-6-methoxy-7-amino-9-isoalloxazineethyl acetate Following theprocedure described in Example 1 except for the substitution of pyridineby acetic acid and the replacement of6,7-dimethyl-9-[p-hydroxyethyll-isoalloxazine by 30.3 grams of6-methoxy-7-amino-9-[B-hydroxyethyl]-isoalloxazine hydrochloride(obtained by reacting 6 methoxy 7 amino 9 [f3 hydroxyethylJ-isoalloxazine [Preparation 12] with alcoholic hydrogen chloride),6-methoxy-7-amino-9-isoalloxazineethyl acetate hydrochloride isobtained. This is converted to 6- methoxy-7-amino-9-isoalloxazineethylacetate by treatment with an alkali or amine base.

Example 37.5,6,7,8-tetramezhyl-9-isoalloxazineethyl acetate Followingthe procedure described in Example 1 except for the substitution of6,7-dimethyl-9-[,B-hydroxyethyllisoalloxazine by 31.4 grams of5,6,7,8-tetramethyl-9-[B- hydroxyethyll-isoalloxazine (Preparation 13),5,6,7,8- tetramethyl-9-isoalloxazineethyl acetate is obtained.

Example 38.5-amin0-6-methoxy-9-isoalloxazineethyl acetate Example39.6-methoxy-8-amin0-9-is0all0xazineethyl acetate Following theprocedure described in Example 1 except for the substitution of pyridineby acetic acid and the replacement of6,7-dimethyl-9-[fl-hydroxyethyl]-isoalloxazine by 30.3 grams of6-methoxy-8-amino-9-[,e-hydroxyethyll-isoalloxazine hydrochloride(obtained by reacting 6 methoxy 8 amino 9 [,8 hydroxylethyl]isoalloxazine [Preparation 17] with alcoholic hydrogen chloride),6-methoxy-8-amino-9-isoalloxazineethyl acetate hydrochloride isobtained. This is converted to 6-methoxy- 8-amino-9-isoalloxazineethylacetate by treatment with an alkali or amine base. 7

Example 40.6-amin0-8-meth0xy-9-is0all0xazineethyl acetate Following theprocedure described in Example 1 except for the substitution of pyridineby acetic acid and azineamyl acetate,

1 9-isoalloxazinebutyl dihydrogen 5,7- dimethyl gen succinate,

' "19 the replacement of 6,7 -dirnethyl 9 [p-hydroxyethyll-[p-hydroxyethyll isoalloxazine hydrochloride. (obtained by reacting-G-amino-S-methoxy-9- [fi-hydroxyethylJ-isowalloxaaine {Preparation 18],with alcoholic hydrogen chloride), 6-amino-8-methoxy-9-isoalloxazineethyl acetate hydrochloride is obtained.This is'converted toot-amino- 8-methoxye9-isoalloxazineethyl. acetate bytreatment with an alkali or amine base.

7 .isoalloxyazine by 30,3 gramsof- 6 -amino-8i-methoxy-9- 1 Example 419-z'soalloxozineethyl. acetate Followingthe procedure described inExample 1 except for the, substitution of"6,7-dimethyl'[,B-hydroxyethyl] -isalloxazine by 25.8 grams of9-[B-hydroxyethyl]isoalloxazine (Preparation -19) 9-isoalloxazineethylacetate is obtained. V p 7 Example 42..-6,7-dimethyl-Q-isoalloxazinehexyl acetate =Followin'g the proceduredescribed in Example 1 except for the substitution of6,7dimethyl-9-[fi-hydroxyethyllisoalloxazine by 34.2 grams-of6,7-dimethyl-9-[{-hydroxyhexyll-isoalloxazine (Preparation 20),6,7-dimethyl-9- isoalloxazinehexyl acetate is obtained.

Similarly, other. esters of [w-hydroxyalkyl]-isoallox azines are,prepared such as 9-isoalloxazinepropyl acetate, '9-isoalloxazine propylbenzoate, laurate, 9-isoalloxazinehexyl propionate, 9-isoalloxazineethylhydrogen succinate, 9=isoalloxazineethyl hydrogen 7'maleate,'6-chloro-9-isoalloxazineethyl acetate, 6-chloro9- *isoalloxazineethyl dihydrogen phosphate, 6-chloro-9-isoalloxazineethyl hydrogen"succinate, 6-chloro-9-isoalloxazineethyl hydrogen glutamate, -methyl7-chloro-9-isoalloxazineethyl acetate, 6-rnethyl-7-chloro-9isoalloxazineethyl hydrogen .succinate,6,8-dimethyl-9-isoalloxazineethyl acetate, 6,8-dimethyl9-isoalloxazineethyl hydrogen succinate, 6,8-dimethyl;-9-isoalloxazinebutyl acetate,fi-methyl-7-ethyl-9-isoalloxazineethyl dihydrogen .phos, phate,6-methyl-7-propyl-9-is0alloxazincethyl hydrogen succinate,6,7-dimethyl-9 isoalloxazineamyl acetate, .6,7-

'dimethyl-9 isoalloxazineamyl hydrogen succinate,6,7-diethyl-94soalloxazinepropyl acetate, 6,7-diethyl-9-isoallox- 6,7diethoxy 9 isoalloxazineethyl hydrogen succinate, 6,7 dipropyl 9isoalloxazineethyl acetate, 6,7 dipropoxy 9 isoalloxazineethyl acetate,

6-amino-7-methoxy-9-isoalloxazineethyl acetate, 6-methyl-.

7-amino-9-isoalloxazinepropyl acetate, 6-methyl-7-amino-9-isoallo'xazinepropyl hydrogen succinate, 6,7-dimethoxyphosphate,6-propyl-7- methyl -9 isoalloxazineethyl' acetate, 6-propyl-7-methyl- 9-isoalloxazineethyl hydrogen .succinate, 6-methyl-7-pr0-pyl-9-i'soalloxazinepropyl dihydrogen phosphate,6,7-diamyl-9-isoalloxazineethyl acetate, 6 methoxy-7-chloro-9-isoalloxazineethyl 'acetate, 6-methyl-9-isoalloxazineethyl9-isoalloxazinebutyl benzoate, fi methyl-9j-isoalloxazineamyl acetate,7-ethyl- 9-isoalloxazineethyl acetate, 7-ethyI 9-isoalloxazineethyl'hydrogen glutarate, 7-ethyl-9-isoalloxazineethyl propionate,7-ethyl-9-isoalloxazineethyl hydrogen succinate,8-metl1yl-9-isoalloxazineethyl acetate, 6-methoxy-7-chloro-9-isoalloxazineethyl acetate, 6-methyl-S-isopropyl-9-isoalloxazineethyldihydrogen. phosphate, 6-methyl-8-isopropyl-9-isoalloxazineethylhydrogen succinate, 6,7 -dibuty1- V 9-isoalloxazine dihydrogenphosphate, 6,7-trimethylene- 9,-isoalloxazineethyl 'dihydrogenphosphate, 7, 8-dimethyl- 9-isoalloxazineethyl acetate, 7,8-dimethyl9-isoalloxazineethyl dihydrogen phosphate, 7,8 dimethyl 9-isoalloxazineV ethyl hydrogen .succinate, 6,8-dimethoxy-9-isoalloxazineethyl acetate,S-methyl-8isopropyl-9-isoalloxazineethyl ,dihydrogen phosphate,6-'chloro -7',8 dimethyl-9-isoalloxazincethyl propionate,5,6,7-trimethyl-9-isoalloxazineethyl acetate,5,6,7-trimethyl-9-isoalloxazineethyl hydrogen 'succinate, 5,6,7-trirnethyl-9-isoalloxazinepropyl acetate,

6,7,8-trimethyl-9-isoalloxazineethyl dihydrogen phosphate,6,7,8-trimethyl-9-isoalloxazineethyl hydrogen .succinate,

6 methoxy 9 -isoalloxazineethyl hydro-'5,7,8-trimethyl-6-amino-9-isoalloxazineethyl acetate,5,6,8-trimethyl-7-amino-Sisoalloxazineethyl acetate,5,6,7,8-tetramethyl-9-isoalloxazinepropyl acetate,5,6,7,8-tetramethyl-9-isoalloxazine cinate, 5,6,7 trimethyl 8 methoxy 9-isoalloxazine ethyl acetate, 6,8-dimethoxy-7-methyl-9-isoalloxazineethylacetate, v6-r11ethcxy-7',tlrdimethyl-9-isoalloxazineethyi acetate,5,7-dimethyl 6-methoxy-9-isoalloxazineethyl propionate,5,8-dimethyl-6,7diethoxy-9 isoalloxazineethyl benzoate,5,6,8-trimethylJ-amino-9-isoalloxazinepropyl acetate,7-isobutyl-9-isoalloxazineethyl acetate, 7-isobutyl-9-isoalloxazineethyl hydrogen 'succinate, 6-isobutyl-9-isoalloxazineethylacetate, 8-isobutyl-9-isoalloxazineethyl acetate,6-isopropyl-8-methyl-9-isoalloxazineethyl acetate,5-isopropyl-8-metl1yl-9-isoalloxazineethyl acetate, and the like,including alkali metal and alkaline earth metalsalts thereof. 7

It is to beunderstoodthat the invention is not to be limited to theexact details of operation or compounds shown and described herein, asobvious modifications and equivalents will be apparent to one skilled inthe art. The invention is therefore to be limited only by the scope ofthe appended claims.

We claim; I p 7 7 1. Compounds represented by the formula:

carbon atoms; (b) a sulfate radical; and; (c) a phosphate.

radical; R and R are members selected from the group consisting ofhydrogen, loWe'r-alkyl, loWer-alkoxy, halo other than fluoro, amino, anda polymethylene group linked to the aromatic ring to forina carbocyclicring having six carbon atoms, R and R are members selected from thegroup consisting of hydrogen, lower-alkyl,

lower-alkoxy and amino, and wherein R R5, R and R when taken togetherinclude not more than one amino group.

2. Compounds represented by the formula:

wit-max array are lower-alkyl and hear an ortho rela- -wherein Riflild'Rg are lower-alkyl, n is an'integer from two to six inclusive andR j is an'acyloxy radical wherein the acyl group isthat offa hydrocarboncarboxylic acid with notmore than eighteen carbon atoms.

propyl hydrogen 'sucmanages 4. Compounds represented by the formula:

wherein n is an integer from two to six inclusive and R is an acyloxyradical wherein the acyl group is that of a hydrocarbon carboxylic acidwith not more than eighteen carbon atoms.

5. Compounds represented by the formula:

N N Br- NI NE E 5 wherein R, and R are lower-alkyl, n is an integer fromtwo to six inclusive and R is acetoxy.

6. Compounds represented by the formula:

I N N (I I NH H1O N/ E/ wherein n is an integer from two to sixinclusive and R is acetoxy.

7. 6,7-dimethyl-9-isoalloxazineethyl acetate.

8. An alkali metal salt of a compound represented by the formula:

( nRl wherein X and Y are lower-alkyl and bear an ortho relationship toeach other, n is an integer from two to six inclusive, and R is anacyloxy radical, that of a hydrocarbon polycarboxylic acid containingnot more than eighteen carbon atoms.

9. An alkali metal salt of a compound represented by the formula:

wherein X and Y are lower-alkyl and hear an ortho relationship to eachother, n is an integer from two to six inclusive, and R is the acyloxyradical formed by removal of one of the replaceable hydrogen atoms ofsuccinic acid.

10. An alkali metal salt of a compound represented by the formula:

wherein R and R are lower-alkyl, n is an integer from two to sixinclusive, and R is the acyloxy radical formed by removal of one of thereplaceable hydrogen atoms of succinic acid.

11. An alkali metal salt of a compound represented by the formula:

SUC-

References Cited in the file of this patent UNITED STATES PATENTS2,111,441 Kuhn et a1. Mar. 15, 1938 Patent Noa 2,825,729

UNITED STATES PATENT oTTTcT CERTIHQATE Q1 @UHREQTHUN Harold GO Peteringet ale It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below,

Column 4, line 34, for "polyhydroxyalkylinoalloxazine" readpolyhydroxyalkylieoalloxazine column 8, line 71, for "8=isobutyl" read6=isobutyl (SEAL Attest? KARL no AKLINE RQBTJTTT c. WATsoN Commissionerof Patents Attesting Oficer

1. COMPOUNDS REPRESENTED BY THE FORMULA: